Fiber Dev Log 2026-08-06

[chenyukang]

This cycle of development leading up to the release of v0.9.0, which focused on production reliability: cross-restart recovery for CCH payments, TLC outcomes reconciliation from on-chain settlement for force-closed channels, more deterministic reconnect flows, and bounded peer traffic.

Backup handling and watchtower cleanup also received additional operational hardening.

Design work continued for mobile and intermittently connected clients. The current direction combines a hosted LSP, tenant-isolated Trampoline routing, remote signing, and buffered payment delivery, alongside a more consistent SDK/provider surface for browser, WASM, and remote-node integrations.

Updates

New Release & Features

• Fiber v0.9.0 is Live: This release introduces a unified database migration system alongside new backup and restore support for storage backends. It also brings extensive security hardening, including stronger validation for network messages and protection against resource exhaustion.
• On-chain TLC settlement for force-closed channels. Fiber can now reconcile fulfilled TLCs into channel, payment, and invoice state after a force close, with settlement proofs bound to the exact TLC identities they resolve.
  • Settle TLCs from on-chain transactions
  • Bind settlement proofs to exact TLC identities
• Streamlined node installation and onboarding. New install and quick-start scripts reduce the setup steps needed to get a Fiber node running.
  • Add install and quick-start scripts

Improvements & Fixes

• CCH recovery and accounting. Send-side state transitions are now durable and idempotent. LND payments and receive-side swaps recover after restarts. Duplicate invoice trackers are coalesced, and multi-hop fee defaults were raised to better cover routing costs.
  • Make recovery durable and idempotent
  • Recover LND payments after restart
  • Make receive_btc creation recoverable
  • Coalesce duplicate LND invoice trackers
  • Raise default fees for multi-hop payments
• Reconnect and reestablishment behavior. Channel-ready messages can be replayed safely after reconnects. Channel reestablishment traffic is paced, and payment recovery retries only the previously failed attempts.
  • Replay ChannelReady after reconnect
  • Pace channel reestablishment messages
  • Retry only failed payment attempts
• Gossip and peer-message resilience. Fiber now bounds inbound peer-message processing, rotates stalled active gossip sync peers, and clears outbound gossip state when peers disconnect.
  • Bound inbound peer-message processing
  • Rotate stalled gossip sync peers
  • Clean up outbound gossip state on disconnect
• Operational safety. Watchtower preimage garbage collection is serialized, backup files are created with restrictive permissions, and invoices now receive a safer default final TLC expiry delta.
  • Serialize watchtower preimage garbage collection
  • Use restrictive backup file permissions
  • Set a default final TLC expiry delta

In Pipeline

• Reconnect stress coverage and peer-abuse handling. Additional tests are being reviewed for rapid reconnect ordering, while repeated invalid channel-message handling remains under development.
  • Cover rapid reconnect reestablishment ordering
  • Ban peers after repeated invalid channel messages
• Hosted LSP and multi-tenant Trampoline design. Work is progressing on a mobile-friendly architecture that keeps tenant identities isolated, delegates route construction through a Trampoline node, supports remote signing, and buffers incoming payments while a client is offline.
• SDK and browser-provider integration. Unifying API design across local WASM nodes and remote Fiber nodes. A WebLN-inspired provider prototype is expanding payment-status and channel workflows.